Power Tailgate Intermittent

steveledzep · December 31, 2020

Went to local shops yesterday morning and the tailgate wouldn't open for me. I tried the activator just above the number plate, the key fob button and the button on the lower dashboard.....nothing ! I had to lower the seats and load my shopping through the rear side door. I drove to another shop and the same thing happened again. When I got home (just 5 miles), everything worked ???

This morning I thought I'd charge the 12v Battery in the boot floor in case it didn't have sufficient power to activate the door. The tailgate opened for me this morning so I connected the charger using an extension lead from the garage. I've just gone out to disconnect and put the charger away and the tailgate won't open again.

The handbook refers to a button in the glovebox to turn the tailgate on or off, I don't appear to have this ? Anyway, if this was in the off position it would never work. My initial thoughts when at the shops was that it must be a fuse, but this theory went out of the window when it worked when I got home. I've put a fresh Battery in my keyfob and I've checked with Mrs LedZep's keyfob too.

I'm a bit stuck, anyone have a solution for me please ?

Please everyone keep safe and let's hopefully look forward to a much improved year next year. Happy new year all.

Herbie · December 31, 2020

Have you got Techstream so that you can run an active test on it?

The only other thing is to use a multimeter or 12V test lamp to check for voltages and/or continuity in the wiring and connectors.

EDIT: The isolator switch for the tailgate is a small round switch on the right-hand edge of the glove box. Open the glove box 'door' and it reveals the switch - it's not actually 'in' the glove box itself.

steveledzep · December 31, 2020

Thanks for response Herbs. No Techstream, but I do have a multimeter. I was looking inside the glovebox, I'll take another look in the morning when it's light.

granadaman · December 31, 2020

Had this problem last 2 winters, just when it gets like this, you’ll find that the rear boot light is dead also, I swapped all the relays around, checked all the fuses just no 12v to micro switches in boot. Put techstream on car and it doesn’t show any faults. Soon as it warms up again outside it’s all sound again. I think it’s a dry joint that’s on the car so at these temperatures it contracts that much it breaks the circuit. If anybody sorts this out as I had my boot in bits for days trying to suss this out I’d be grateful. Only thing was when I swapped some relays the door worked again for a minute or 2 that’s why it’s a git to find the underlying cause.

steveledzep · December 31, 2020

Thanks for that Mick, wish it was a bit more encouraging though 😑. We've had snow here today so it is probably temperature dependent as you suggest. When I next get into the boot I'll check the boot light, but if the circuitry has allowed me to open the tailgate then the connection to the light is probably sound too. I'll report back.

steveledzep · December 31, 2020

Following Mick's thoughts of a poor connection, I've been giving this some (logical?) thought.

The door release on the tailgate doesn't unlock the door, but it does unlock the side doors, swing the mirrors out and turn on the sidelights. The rubber nipple thingy locks everything too as well as activating the alarm. From that I conclude that the switch itself is unlikely to be the fault. Furthermore, the internal release on the dashboard doesn't unlock the tailgate either. I would say that there's a zero percentage chance of both switches failing at the same time.

The internal switch activates the tailgate opening mechanism too, but the tailgate switch only releases the door for manual opening. I assume the opening mechanism is dependent upon the tailgate being unlocked. I therefore conclude that the fault is in the tailgate unlocking mechanism. Is it a little servo or something ?

May not explore my theory tomorrow as I'm off now to watch Jools and imbibe a dram or two of Bushmills.

steveledzep · January 1, 2021

Found the isolator switch by the glovebox Herbs, thanks.

It's looking like Mick has it correct. Tailgate wouldn't open first thing this morning, lots of snow around. Sun came out and later in the morning the tailgate opened using the switch above the number plate, so I opened it manually. As Mick said, the boot lights weren't on, really strange. In cabin lights were on when I opened a side door. I checked the Battery and it was showing 11.8v so I put it on charge again. Few hours later showing 14.2v so I took it off charge.

Everything now worked, all switches exactly as they should and the boot illumination was now on too.

A bit flummoxed now, I'll watch the situation. If tailgate doesn't work in icy conditions only, I can live with that.

granadaman · January 2, 2021

Bitch when your right but like you there seems no rhyme or reason for what’s causing it, but mine hasn’t played up this winter yet. When it does I’ll check my Battery as mine has been on its last legs for 18 months but keeps soldiering on.

steveledzep · January 2, 2021

It was snowing here this morning Mick and everything worked exactly as it should. I'm of the opinion that it's the Battery causing it. Early November I had a no-start problem and had to charge the Battery. I put it down to minimal use as I've only done 3k miles in the last 12 months and my average trip is 5 miles. The Battery is only 2 years old and I have a 3 year warranty on it so I'll monitor the situation. Thanks for your contribution.

Illogan · January 3, 2021

I strongly suspect it's your Battery Steve. I had similar problems earlier last year - (wasn't using the car much in lockdown) - I persevered for a while, using a solar top-up panel, but when I replaced the batter - "et voila!" - - all was well, and the tailgate opened as she should!

And no problems since

impero · January 3, 2021

1 hour ago, Illogan said:

I strongly suspect it's your battery Steve. I had similar problems earlier last year - (wasn't using the car much in lockdown) - I persevered for a while, using a solar top-up panel, but when I replaced the batter - "et voila!" - - all was well, and the tailgate opened as she should!

And no problems since

BTW IIIogan, i would love to have some more details about what solar top-up panel you used. Kindly appreciated some info , some model, even some photos if you have.

Cheers

granadaman · January 3, 2021

18 hours ago, steveledzep said:

It was snowing here this morning Mick and everything worked exactly as it should. I'm of the opinion that it's the battery causing it. Early November I had a no-start problem and had to charge the battery. I put it down to minimal use as I've only done 3k miles in the last 12 months and my average trip is 5 miles. The battery is only 2 years old and I have a 3 year warranty on it so I'll monitor the situation. Thanks for your contribution.

Thanks will look at changing mine I guess

Barry14UK · January 4, 2021

6 hours ago, granadaman said:

Thanks will look at changing mine I guess

Before changing the 12v Battery, I would check the voltage, then bring it up to full charge with a smart charger which charges at 5amp max. Then monitor it to check how it is holding its charge. If my car is not used for about 10 days or just lightly to local store I am having to trickle charge it. (It's gone back for further repairs at present and I just hope the Battery is being charged as I requested as I don't want to replace it just yet - long story).

steveledzep · January 29, 2021

Thought I'd resurrect this thread as I didn't want to hijack others.

I've read with interest the threads here about the auxiliary Battery being the weakness/Achilles heel and that's what I've experienced. Mine is fitted with a standard wet Battery and it's suffered a couple of discharges in the last 3 months. It does charge up, but doesn't hold charge as well as I think it ought. I bit the bullet and bought a replacement.

It's not easy to find a suitable Battery to enable by-passing of the Lexus £300 a pop scenario. I'll link here to the one I bought and it fits the Battery tray very well, I just had to pack out the securing bracket by 10mm to fix it in place. It's a sealed AGM type so I'm now happy that I have the correct type fitted. https://www.ebay.co.uk/itm/Hankook-SA55020-063-Start-Stop-AGM-Car-Battery-5-Year-Warranty/254122603753?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

My tailgate is no longer intermittent...it just doesn't work at all, ever ! The glovebox button is active but none of the switches activate the tailgate. Interesting to note that the boot illumination is not working either. The manual advises to initialise the tailgate after disconnecting the 12v Battery. All I have to do apparently is to shut the door manually and then everything will then be reset. Not happening for me ! It's not doing my back much good clambering over the back seat every time I need to open the tailgate. Any ideas ?

steveledzep · January 30, 2021

/\ Anyone ?

PCM · January 30, 2021

20 minutes ago, steveledzep said:

/\ Anyone ?

Water ingress, damp, condensation?

Been a lot of it about ...

steveledzep · January 30, 2021

3 hours ago, PCM said:

Water ingress, damp, condensation?

Been a lot of it about ...

Thanks for that Piers. I'd say unlikely as I have no condensation on the rear screen and the Battery well was bone dry too. I hope you think it's the situation that is sad, not me ? 😉

PCM · January 30, 2021

You never know?!

My rear camera stopped working. No condensation but I suspect there was moisture. Possibly me being over enthusiastic washing it with a hose.

Seems drier now - and camera working again...

royoftherovers · January 30, 2021

36 minutes ago, PCM said:

You never know?!

My rear camera stopped working. No condensation but I suspect there was moisture. Possibly me being over enthusiastic washing it with a hose.

Seems drier now - and camera working again...

Nothing ventured,nothing gained Piers.

Herbie · January 30, 2021

@steveledzep I know it sounds counter-intuitive because the Battery was disconnected while you changed it over, but it might just help to disconnect it again for a few minutes. It's not guaranteed but I have seen it work before.

steveledzep · January 30, 2021

1 hour ago, Herbie said:

@steveledzep I know it sounds counter-intuitive because the battery was disconnected while you changed it over, but it might just help to disconnect it again for a few minutes. It's not guaranteed but I have seen it work before.

You may well be right Herbs. It'll just take me a few minutes to try it tomorrow morning. Failing that, I'll need to check the connections and operation of the unlocking mechanism.

Walus · February 22, 2021

Hi @steveledzep , Same thing is happening to my car, intermittently at the moment. Did you fix the issue and if so how? Thanks.

steveledzep · February 22, 2021

No, not fixed it Tom. It wasn't intermittent for long, it hasn't worked for many weeks now. It does seem like a plague and I read the posts on the other threads.

I prised out the switch on the underside for closing the tailgate. Like the dashboard switch, this should always work irrespective of the engine being powered or not. This switch just has two wires (flimsy, not cables) going to it. My multimeter showed it to be dead. The handbook shows a 30amp fuse for the PBD, but there's just a long, green block there instead of the individual fuses depicted.

I'll continue watching here in case a solution is forthcoming. Otherwise, I'll take it to a local auto-electrician who my neighbour recommends. It's not too much of an inconvenience at the moment, but it will become increasingly important as our freedom slowly returns.

Walus · February 23, 2021

15 hours ago, steveledzep said:

No, not fixed it Tom. It wasn't intermittent for long, it hasn't worked for many weeks now. It does seem like a plague and I read the posts on the other threads.

I prised out the switch on the underside for closing the tailgate. Like the dashboard switch, this should always work irrespective of the engine being powered or not. This switch just has two wires (flimsy, not cables) going to it. My multimeter showed it to be dead. The handbook shows a 30amp fuse for the PBD, but there's just a long, green block there instead of the individual fuses depicted.

I'll continue watching here in case a solution is forthcoming. Otherwise, I'll take it to a local auto-electrician who my neighbour recommends. It's not too much of an inconvenience at the moment, but it will become increasingly important as our freedom slowly returns.

Thanks steveledzep. It is lashing today so I cannot look into it right now. The tailgate motor itself is very pricey so solving this problem would save us all here thousands.
My experience with it is that sometimes the tailgate ECU does not power on - gate does not lift or close and the boot lights are out too. This can be due to dry solder joints in a specific spot on the PCB or a failure of some relay. Wiring or connectors are most likely not at fault here but that is just a hypothesis. I’m hoping to look into this more when the weather improves.

Greisingel · March 3, 2021

I’ve ordered 2 new gas struts.

I came across an explanation that had me wondering. I don’t know if it is right.

The mechanics of the tail gate are that when the lock releases as you electrically signal to open, the struts do most of the ejection work after lock release.

If the initial ejection is weak and a tipping point of expansion isn’t reached the motor may give up and drop the lid. There is a 16 second motor burnout protection. The strut may open fully in the end but more slowly and hold reasonably well giving the impression it is good.

I was sceptical at this. I thought the motor lifted and dropped the lid. The struts acted only as a damper. If it is correct then it can explain in some cases how seal compromised struts may cause the lid action to cease.

In my case the lid motor ceased operation entirely working only after some time had elapsed, possibly after the strut gas had in some way altered.

This may all be nonsense. My Techstream showed no codes for lid.